Delivery box



July 23%, 1935- J. A. HoPwdoD DELIVERY BOX Filed Nov. 30, 1954.

2 Sheets-Sheet 1 M V p10 INVENTOR. J0/7/7 x4. Hopwaod BY ATTORNEY.

Patented July 23, 1935 V i r 2,008,327

. j UNITE STATES PATENT OFFICE DELIV RY BOX John 'A. Hopwood, Great Neck, N. Y. ApplicationNovemberw,1934, Serial No. 755,343.

' '5 Claims. 01. 217-19) This invention relates to-delivery boxes and is box is manufactured with the wood in dry state adapted especially for incorporation in boxes, for and the rivets pulled down tight, the subsequent the retail delivery'of bottled milk. g swelling of the wood, when wet, is not only apt .In this art, the so-called slat box has become to, but usually does either shear Qffithe rivet quite popular and, is-generally preferred by the d p them through e Corner s, 5 larger distributors. These boxes embody a stretch the rivets undesirably or to a point of rectangular body formed by superimposed slat breakage or cause splitting of the corners in a': frames which are maintained in assembled relamann r hereinafter more u ly eXplainedtion invarious ways. For example, in some types fice it here to say that pract ce has demo st at of box, the slats of each frame are secured tothat such is the case. M v 7 1,0 gether at the corners. and to the slats above. the As a result, it has become almostthe universal frames by metal corner angles to which the slats practice in the use of slat boxes to space the slats are attached. The more widely used structures apa e her by Spacers formed 0n the Corner of this kind are those wherein the slats areseangl r y p d nt pa r f r l ve y cured to metal corner angles by so-called lacing small size. I I e g 1-5 wires orrivets which pass vertically through the The difficulty with these arrangements is that slats of the several superimposed courses in sucwhen the box is wet, the spacers are either'uncession and through the corner angles to hold the desirably deformed or the wood yields to permit parts together; i embedding of the spacerstherein. Splitting of A box thus constituted embodies a strong and the slats frequently results, but, in any event, 20 durable construction, but. has presented a numthe box loosens materially when the wood dries ber of rather serious problems. For example, it making a very noisy box due to rattling inuse. is the common, practice to' collect empty bottles 7 With the foregoing considerations in mind, and

I in delivery boxes; frequently in inverted position as a-result of exhaustive research in order to in the-boxes, and .to pass these bottles directly obviate and a e ate these n n I haVB 25,. through the. washers without removing them discovered that it is possible to eliminate spacers from the'boxes; in order tofacilitate the handling and at, the same time make use of the inherent of bottles collectively. In the washing operation, character of wood to permit the box to bemade the bottles are subjectedto live steam'and scaldtight at its corners atall times and yet permit 0 ingw'ater, and as a, result boxes are wet during of such expansion in the walls of the box as must 2.0

such "operation. Thus; in the normal use of the necessarily occur when the wood thereof is wet. box, it .is wet during the washing. of the bottles This I accomplish by clamping the slats or and after washing, the boxes and 'bottles 'are' set barsof the boxin edge abutting relational) the aside and proceed to dry. Subsequently, the four corners of the box and between metal lim- 3 5 bottlesare filled with milk, sealed, and ice packed iting elements tied together by bolts and rivets about the necks,-so that the boxes are again wet and overlying the end portions of the bars or and remain so until the ice is melted and the slats, whereas those portions of the bars or slats boxes again proceed to dry. V H i which are not directly between said limiting ele- The wood frornwhich such boxes are made ments are made of decreased height to provide,

40 is thus alternately wet and dry throughout the between contiguous edges of the bars,expansion e9 life of the box and there results. alternate periods space which will permit the slats to expand in of swelling and contracting of the wood thereon a vertical directionwithout engagement of these It will of course be remembered in this connecparts of adjacent slats with one another. By tion that whenwood is wet, it swells or expands thisarra-ngement, the building up of leverage, as

in a directionnormal to the grain. Thereis very -will behereinaftermore fully explained, and 45 little, if any, longitudinal expansion, but lateral which I have found to be the primary cause of and vertical expansion of the slats is appreciable. rivet breakage and splitting in prior boxes, is When the wood driesout, the-slats again contract entirely eliminated, the rivets of the present inwith the result that there is practically a constant vention taking merely the direct thrust which 5 expansion and contractionwhich must necessaris not sufiicient to cause damage to the struc- 59 ily occur in use of wood for the purposes stated. ,ture, r I I i When wooden slats are confined within corner Features of the invention, other than those ,angles and riveted or bolted together as stated, advertedto, will be apparent from the hereinthis expansion and contraction of the wood is apt after detailed descriptionandclaims, when read tocause serious difiiculty. For example, if the in conjunction with the accompanying drawings,

The accompanying drawings illustrate one practical embodiment of the invention, but the construction therein shown is to be understood as illustrative, only, and not as defining the limits of the invention.

Figure 1 is a fragmental perspective showing one corner of a slat box illustrative of the typeof box to which the present invention relates.

Figure 2 is a side elevation of the structure shown in Figure 1, illustrating the manner in which expansion of the wooden slats results in breakage.

Figure 3 is a fragmental perspective showing the effect of expansion in a greatly magnified, form.

Figure 4 is a side elevation showing clearance for expansion.

Figure 5 is a side elevation of one corner of a box showing the manner in which the boxof the presentinvention is made to preclude breakage.

Figure '6 is a section on the line 6-6 of Figure 5.

Figure 7 is a view similar to Figure 5, but illustrates the slats expanded under the influence of moisture. Y

, Figure 8 is'a section on the line 8-8 of Figure '7 showing expansion greatly exaggerated in the "interest of clearness.

Figure 9 shows diagrammatically the theory in accordance with which the present invention functions.

In Figure 1 of the drawings, I have illustrated, in perspective, one corner of a slat box I. Such a box embodies superimposed slats 2 abutting at the corners of the box in any appropriate way. Such a box may be provided with corner irons serving to enclose the corners of the box to cover and protect the same. However, these corner irons have been omitted in the present showing.

In practice, such boxes are generally provided at their upper and lower'edges and at each of their four corners with metal limiting members 3, shown as angle irons and these limiting members are perforated to receive rivets or tie rods 4 which are passed therethrough and through the several slats 2 in succession. These rivets thus extend for the full height of the box and are headed over at their opposite ends as indicated at 5. In practice the limiting members 3 may be made integral with and form part of the metal corner closures. However, for the purpose of the present showing, they are illustrated as separate and independent.

The box thus formed appears in side elevation, as shown in Figure 2, and is initially made as shown in full lines in said figure, the slats 2 being in edge abutting relation and clamped firmly against one another by the limiting members 3 held in place by the tie bolts or rivets 4.

When a box of this kind, however, is wet, the wood from which the bars 2 is made is susceptible to marked expansion, so that in a box with slats 2" or 3" in height, the expansion, if not restricted by limiting means of any kind, will not infrequently exceed /2" to A.. The structure shown in Figure 2 is such that it, structurally, cannot stand this strain. As a result, therivetheads are broken ofi or the bars are split or the rivets are stretched and broken. As a result, attempts to make the box, .such as shown in Figures 1 and 2, has been given up as impractical and manufacturers have turned to the arrangement shown in Figure 4 which consists in spacingthe slats 2 apart to leave interspaces 6, generally maintained by spacers 4a, which vary considerably in structure. The principle, however, underlying the operation of these spacers is the same. They simply serve to space the slats apart, so that when expansion takes place the slats can expand. The difiiculty, however, with this arrangement is that when the slats expand, they force the spacers into the wood and generally split the slats.

My research in connection with boxes of the kind shown in-Figures 1 and 2 convinces me that boxes of this kind fail due to the application of great leverage which, in practice, is more than the rivets and limiting members can withstand.

Wood is a fibrous substance. It comprises an infinite number of relatively small fibers which extend generally in the direction of the grain of the wood and each of which is substantially tubular in form. When the wood is dry, the fibers are individually contracted, but, when the wood is subjected to moisture or water, these fibers take up the water and. expand radially. While thefiber of wood has not a truly circular cross section, I have in Figure 9 attempted to show schematically what takes place. In this figure, '1 indicates the normal size of a dry wood fiber which, upon being wet, expands radially in all directions to a larger diameter shown at 1a, thus making the fiber larger and when this occurs in all of the fibers of a piece of wood; the aggregate of expansion, while minute in each, becomes very considerable for the whole. If wood is unrestricted, the expansion will be in all directions, but I have found that it is possible to restrain it in one direction if it is permitted to expand in another direction. Thus, by reference to Figure 9, assume that 3 are abutments or liming members between which the wood fibre is positioned. 1 indicates the normal outline of the dry fiber. If moisture is applied to this fibre, and it proceeds to expand or swell, it will be found to enlarge laterally while maintaining substantially its same vertical height. What is true with one fiber occurs with'the several fibers of a piece of wood, and the wood will expand laterallyif it is firmly held between abutments against expansion vertically.

Theory therefore indicates that it is thoroughly practical to confine wood against expansion in one direction at least within reasonable limits providing limiting members of appropriate strength are provided. I have discovered that the difiiculty with the box of Figure 2 resides in the fact that the thrust of the swelling wood is not taken by the limiting members as purely a direct thrust of the interposed fibers,-but rather through the greatly increased force resulting through the action of leverage. This I have attempted to show in Figure 2 of the drawings on a greatly enlarged scale in order that the same may be clear.

By reference to Figure 2, the reference character 8 indicates a line drawn midway between the upper and lower edges of the box and which may be referred to as a neutral plane. When the wood is' wet, the wooden parts of the box above the line expand upwardly, while the wooden parts of the box below theline expand downwardly. Thus, the upper edge of the middle slat 2 will expand upwardly, as indicated by the dotted line 20., causing the next slat above to be bent upwardly intermediate its ends, while at the same time, said superimposed slat will also expand, so that its upper edge will occupy the position 21) causing the top slat to be further bent upwardly, and it will simultaneously expand so that its upper edge 20 will be very appreciably raised. At the same time, the same effect is occurring in a downward direction, each slat undergoing the change shown in Figure 3 in a greatly exaggerated manner. For example, the vertical zone between the edge-9 and the line it] in Figures 2 and 3 is the zone of limitation between the limiting members 3, and in this zone the fibers will expand laterally, as indicated by the dotted lines I I, while beyond this zone of limitation, the slats will expandvertically, as indicated by the dotted lines 2a, 2b and 2c. The practical result of this arrangement is that each of the two upper bars constitutes in sheet a lever of the first class fulcrumed at the point i2 and with a power arm indicated at E3 and extending for practically hall the length of the box. The maximum of force is exerted upon this power arm about the middle of the length of the box and is indicated by the arrows M. The arpws [5 indicate the work done by this lever which obviously constitutes the building up of a relatively great vertical force upwardly against the upper limiting member I; and

downwardly against the lower limiting member 3.

As a result of this great force built up through leverage as described, rivet heads cannot stand the pressure and they break. If they do not break, the slats will split or the rivet heads will,

pull throughthe limiting members. Something must give and breakage results.

As a matter of actual practice, the vertical expansion and bending of the several superimposed slats produce so great a force of leverage as to actually cause lateral deflection or bending of the bolt or rivet 4, as shown in dotted lines in Figure 2, and the actual limiting effect of the members 3 in the limiting zone and adjacent the line it! is somewhat relieved permitting further expansion in this zone which is undesirable and tends to further bring about lateral deflection of the bolt as stated.

Graphically stated, the several slats of the box may be said to fan, with respect to the bolt, bringing about the bending of. the bolt with accompanying stretching thereof. Unless the bolt is of very unusual size and strength, the head will break off or the bolt will break intermediate its length as indicated in dotted lines in the figure. There is generally an accompanying deformation of the limiting plates 3 which occurs prior tobreakage and even though the parts hold and do not break, when the box is dried out and the slats tend to reassume their normal position, the bolt will be bent back into substantially straight position leaving a loose jointed structure. When this occurs frequently, as the box is wet and .dry, the fatigue on the bolt is not only destructive thereto,

but the wooden parts of the box cannot stand the strain and split.

My study and research have shown that the wood in the limited zone between the lines 9 and I0 can be properly confined by rivets or limiting plates, if the thrust is direct and is not accompanied by the building up of great pressures under leverage, but practice has demonstrated that where the leverage occurs breakage results.

Thus, in carrying out the present invention, I clamp the ends of the slats'together at the corner of the box by ties or rivets 4 and limiting plates 3, as hereinbefore described, and as shown in Figure 5, so that the slats are actually in edge abutting relation within the limiting zone indicated by the lines 9 and Ill, but beyond the line iii, one or both of the adjacent edges of each two slats is cut away as indicated at IE, to provide expansion spaces H. In practice the adjacent edges of both slats may be cut as stated, but, in

the interests of economy, I find it convenientto cut the opposite edges of every alternate slat; In this way, the first, third and. fifth slats may be left with straight edges, while the second and fourth slats may be out as stated, but, in any event, the slats should be cut away to such extent that the aggregate cutout of the several slats will at least'be equal to the aggregate expansion of said slats. In other words, the sum. of the vertical dimensions of the cut outs shouldbe' at least equal to the sum of the vertical expansion of the several slats .2. For example, and without intending to limit the invention to specific dimensions, I may state that in a box made from ash wood with five slats /4" to 1 thick, and approximately 2" high, the cut outs between each two slats can conveniently be approximately This will allow the wood to expand-between the line Ni at one end of the box; and a corresponding line at the other end of the box for a maximum vertical expansion of at joints without setting up the leverage to which I have hereinbefore referred.

Consequently, when the slats are expanded to substantially close these openings IT, as graphically shown in Figure 7, the only vertical pressure between the slats will be at the ends which are confined within the limiting zone between the limiting plates 3 and the autogenous pressure thereby set up will-be in a truly vertical direction, so that there is no leverage increase in power and the ends of the slats within this zone are free to expandlaterally as indicated at l l in Figures 8 and 3.

their full thickness and for the full length of the 1 zone, there is no localized application of pressure which would damage the wood fiber or cause splitting, and consequently, there is an even distribution of the forces to which the slats are subjected in this zone and they are well able to Withstand these forces. There results a box which is tight at its corners at all times, which does not require the use or spacers, which does not build updestructive leverage and which is thoroughly prac: tical and durable. The stresses and strains to which the box is subjected by atmospheric changes or by the presence or absence of water are properly distributed and the corner construction is sufiiciently strong and durable to stand the hardest usage.

The foregoing detailed description sets forth the invention in its preferred practical form, but the invention is to be understood as fully commensurate with the appended claims. 7

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. A milk delivery box comprising a plurality of superimposed courses of Wooden slats, limit- 75 I ing members positioned at each of the four corners and at the upper and lower edges of the box and overlying end portions of the upper and lower slats to define vertically limiting zones, tie members extending vertically through the slats in the limiting zones and anchored with respect to the limiting members to clamp those portions of the several slats which occupy the limiting zones in edge abutting relation, at least one edge of each two adjacent slats being cut away between substantially the limiting zones at the opposite ends thereof to provide an expansion space of sufficient height to preclude forcible contact between adjacent slats exteriorly of the limiting zones.

2. A milk delivery box comprising a plurality of superimposed courses of wooden slats, corner angles positioned at each of the four corners and at the upper and lower edges of the box and overlying end portions of the upper and lower slats to define vertical limiting zones, tie members extending vertically through the slats in the limiting zones and anchored with respect to the corner angles to clamp those portions of the several slats which occupy the limiting zones in edge abutting relation, at least one edge of each two adjacent slats being cut away between substantially the limiting zones at the opposite ends thereof to provide an expansion space of suiiicient height to preclude forcible contact between adjacent slats exteriorly of the limiting zones.

3. A milk delivery box comprising a plurality of superimposed courses of wooden slats, corner angles positioned at each of the four corners and at the upper and lower edges of the box and overlying end portions of the upper and lower slats to define vertical limiting zones, elongated rivets extending vertically through the slats in the limiting zones to clamp those portions of the several slats which occupy the limiting zones in edge abutting relation, at least one edge of each two adjacent slats being cut away between'substantially the limiting zones at the opposite ends thereof to provide an expansion space of sufiicient height to preclude forcible contact between adjacent slats exteriorly of the limiting zones.

l. A milk delivery box comprising walls formed of superimposed wooden slats in edge abutting relation adjacent their opposite ends and free from engagement with one another for the remainder of their length to leave spaces between said slats greater than that to be taken up by expansion of the wood of the slats when wet, limiting members positioned at the four corners of the box and at the upper and lower edges thereof and substantially co-extensive with the edge abutting portions of the slats, and tie members extending through the several superimposed slats and through the limiting members to tie said limiting members together and hold the abutting portions of the slats in engagement with one another.

5. A milk delivery box comprising walls formed of superimposed wooden slats in edge abutting relation adjacent their opposite ends and free from engagement with one another for the remainder of their length to leave spaces between said slats greater than that to be taken up by expansion of the Wood of the slats when wet, corner angles positioned at the four corners of the box and at the upper and lower edges thereof and substantially coextensive with the edge abutting pcrtions of the slats, and tie members extending through the several slats and through the corner angles to tie said corner angles together and hold the abutting portions of the slats in engagement with one another.

JOHN A. HOPWOOD. 

